We have a script that enters time behind the scenes on support cases so that we can track how long it takes to work a case. There's a weird situation where employees send in cases and the case is created under the employee (and not under a customer record).

When a timebill is created behind the scenes it errors out because you cannot set the employee in the Customer field on time entry. I notice that if I create the timebill manually against the case, the employee is set in the Customer field and the case is automatically set in the casetaskevent field. The url parameters of the timebill look like this: